Preparation Method of Upconversion Nanoparticles and Its Biological Application

Next-generation therapeutic devices will rely on an intelligent integrated system that consolidates multiple functions into a single platform. These individual chemical components exhibit diverse physicochemical properties, demonstrating multifunctional characteristics. In this review, we focus on how the distinctive properties of upconversion nanoparticles (UCNPs), achieved via refined preparation methods, unlock novel functionalities in biomedical applications. Specifically, features such as near-infrared excitation, deep-tissue penetration, low autofluorescence, and tunable multicolor emission endow UCNPs with substantial potential in fields including deep-tissue imaging, targeted drug delivery, and photodynamic therapy. This article systematically reviews recent advances in the design and functionalization of UCNPs, elucidating their role in facilitating the development of integrated diagnostic and therapeutic platforms and fostering the establishment of intelligent responsive treatment systems. Finally, we address current technical challenges—including uniformity in large-scale production, long-term biosafety, and in vivo metabolic mechanisms—and provide insights into future interdisciplinary integration, clinical translation pathways, and their potential role in personalized medicine.